Just ordered a 2011 Dodge 3500 6.7 Cummins i want to do an exhaust system but all the dealers said it would void my warrenty if i took out the DPF. Was woundering if any body has done a DPF back system and if it made a differance in sound. 
11 Dodge 3500 Exhaust System
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HRT Offroad
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The exhaust on the 2011 has crazy amounts of restriction with all of the emissions crap on it...So I would venture to say that you won't have much sound difference with an exhaust from the DPF back.
Rockwerx
Active VIP Member
The stock "muffler" is a straight through design...more for appearances that actually quieting the engine...better term for it would be resonator. Very little sound difference if you go straight pipe from the DPF back.
I have tried a few exhaust combinations on my 6.7 CTD. First I tried an H&S stage 1 delete pipe. It replaces the NOX filter and DPF. Noticed a 3 mpg gain in fuel economy right away. Slightly louder exhaust note and a slight drone under some towing conditions. Next combination was going with a new down pipe after the turbo to get rid of the CAT in the down pipe. Truck was too loud for us so rather than adding a muffler I installed a 5" turbo back system...part # 15986. The truck is slightly louder than my first setup but has a deeper tone to it.
When I checked my fuel records I found that it hardly changed after getting rid of the CAT in the down pipe. The EGTs were down slightly but I expected more of a change in fuel economy. Based on my records the CAT in the downpipe is not near as restrictive as the NOX filter and the DPF. Knowing what I know now I would have just stayed with the stage 1 delete pipe and saved some money for other mods.
If you want to keep your warranty and also gain a couple of mpg then unplug the EGR. You should notice a 3 mpg increase in fuel economy. Unfortunately if will cause a CEL but it should not derate your truck. If you need to go to the dealership then plug it back in and after a few start and drive cycles it will go out. IMO the EGR system is harder on the engine than the DPF. Both systems are a poor and cheap solution for "cleaning up" the exhaust gasses. Who ever figured that it was Okay to burn 30 to 50% more fuel in order to have a "cleaner" exhaust should be whipped! The politicians who approved this should also be whipped!
I have tried a few exhaust combinations on my 6.7 CTD. First I tried an H&S stage 1 delete pipe. It replaces the NOX filter and DPF. Noticed a 3 mpg gain in fuel economy right away. Slightly louder exhaust note and a slight drone under some towing conditions. Next combination was going with a new down pipe after the turbo to get rid of the CAT in the down pipe. Truck was too loud for us so rather than adding a muffler I installed a 5" turbo back system...part # 15986. The truck is slightly louder than my first setup but has a deeper tone to it.
When I checked my fuel records I found that it hardly changed after getting rid of the CAT in the down pipe. The EGTs were down slightly but I expected more of a change in fuel economy. Based on my records the CAT in the downpipe is not near as restrictive as the NOX filter and the DPF. Knowing what I know now I would have just stayed with the stage 1 delete pipe and saved some money for other mods.
If you want to keep your warranty and also gain a couple of mpg then unplug the EGR. You should notice a 3 mpg increase in fuel economy. Unfortunately if will cause a CEL but it should not derate your truck. If you need to go to the dealership then plug it back in and after a few start and drive cycles it will go out. IMO the EGR system is harder on the engine than the DPF. Both systems are a poor and cheap solution for "cleaning up" the exhaust gasses. Who ever figured that it was Okay to burn 30 to 50% more fuel in order to have a "cleaner" exhaust should be whipped! The politicians who approved this should also be whipped!
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